'B' Team problem

[TacticalGenius]

I'm Arsenal and I want to give myself a 'B' team similar to the system in Spain. I've worked out how to do it and thought a MLS club (Colorado Rapids) was a good idea as MLS has no promotion or relegation, and that Arsenal are already affiliated with them irl. But it wasn't. As the MLS starts before the Premiership, I found that when I started a game, the Arsenal squad had been mixed in with some of the Rapids players, that my players had played in the MLS and messed up their work permits, etc. So I need a different club. I thought about the now-defunct Chester City in the BSP, but is there any way of making them unable to ever be in the same league as I am, as per the Spanish regulations? Or is that done automatically by setting as a 'B' club?

EDIT: I've just looked at the agreement between Real Madrid and RM Castilla, and I've copied the settings (untick Main Club, tick Same board and Players move Freely). Will that make them unable to promote into my division at any point? If this works I'll rename them and clear their players as I've got plenty of players to send as I won't be entering the reserves competition, assuming unticking 'has no reserve fixtures' doesn't mess up the leagues?

Thanks in advance,

TG.